Deinking paper



Patented Aug. 14, 1928? UNITED STATES PATENT OFFICE.

ALAN R. LUKENS, OF WYOMING, OHIO, ASSIGNOR TO THE RICHARDSON COMPANY,

F CINCINNATI, OHIO, A CORPORATION OF OHIO.

DEINKING PAPER.

No Drawing.

It is the object of my invention to provide a process of deinking paper in which the pulped paper is treated with an alkali and is then or simultaneously treated with a sulfonate, or water soluble compound of sulfonic acid and hydrocarbons, organic or mineral, such as is ordinarily made by treatment of a hydrocarbon oil with fuming sulfuric acid.- The ingredient found most satisfactory is sodium sulfonate, and the result of its use is to very greatly facilitate the operation of removing the alkali compounds and constituents of the ink. The reasons for the action of the sulfonate is abstruse and ditiicult to explain, and 1 base my invention on the results obtained by its use, whereby the amount of water required for washing out the freed inky matter is reduced in a very marked manner.

The process of deinking paper stock may be successfully carried out by soaking macerated paper pulp containing old news print or the like in a weak solution of an alkali, such as sodium carbonate. After soaking 25 the paper pulp for an extendedv time the pulp is discharged into a filter tank and washed preferably with Water. The deinking action accomplished b thealkaline reaction is quite pronounce If during the process of soaking or at the start I introduce a small percentage of a sulfonic acid salt of a suitable hydrocarbon, the washing does not need to be carried out during such a lon period, and the whiteness of the paper is we] assured.

The addition of heat to the pulpy solution further appears to accelerate the reaction, although I have been able to secure ylery good results without the addition of eat.

' My process is consequently useful not only from the saving in time, which the old alkaline treatment re uired, but also from the very materially w iter stock which may be obtained.

Following is a specific example of my treatment. To 200 gallons of water warmed to a temperature of 120 Fahrenheit, 100 pounds of macerated paper pulp, containing enough old news print to require deinking, is added and thoroughly mixed. To this solution 6 lbs. of sodium carbonate is added and the pulp is thoroughly mixed in the so- Application filed June 22, 1925. Serial No. 38,934.

lution. After treatment for about half an hour I add a solution in water of 1 lb. of sodium sulfonate. The mixture is then agitated for another half hour and the contents of the mixing tank charged into a filter trough where the liquid is filtered off. The paper pulp remaining in the beater is then washed with water in a washer and the pulp is ready for forming into sheets.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

1. That process of removing coloring matter from fibrous pulp which consists in soaking the fibrous pulp in an alkaline solution in the presence of a sulfonic acid compound, and then Washing the pulp with water without the use of super-added soap or fatty acid.

2. That process of removing coloring matter from fibrous pulp which consists in soaking the fibrous ulp in a heated solution of an alkali, and a ding to the solution the salt of a sulfonic acid compound, and then washing the pulp with Water without the use of super-added soap or fatty acid.

3. That process of removing coloring matter from fibrous pulp which consists in soaking the fibrous pulp in a heated solution of an alkali, and adding an alkaline sulfonate to the solution, and finally washing with Water the fibrous pulp thus treated, without the use of super-added soap or fatty acid.

4. That process of removing coloring matter from fibrous pulp which consists in soak ing the fibrous pulp in a solution of an alkali and adding to the solution the salt of a compound of a hydrocarbon and fuming sulfuric acid.

5. That process of removing coloring matter from fibrous pulp which consists in soaking the fibrous pulp in a heated solution of an alkali and adding to the solution the salt of a compound of a hydrocarbon and fuming sulfuric acid.

6. That rocess of removing coloring mat ter from brous pulp which consists in first ,loo soaking the pulp in an alkaline solution and then adding to the solution a water soluble sulfonate and finally washing the treated pul with water without the use of superad ed soap or fatty acid.

. ALAN R. LUKENS. 

